My use-cases here are "how quick and easy is it to log out a public-area computer which someone left logged in?" and "how quick and easy is it to reboot or shut down a room full of 30 computers, one at a time?". XP took 4 or 5 keystrokes, but would buffer them, so you could hit the keys quickly even if the OS didn't respond fast enough; Win7 didn't do that same buffering, but was at least as good in most cases anyway because of needing fewer keystrokes to begin with.

I hope there are faster ways, perhaps less obvious ones, still to be discovered for Windows 8... because that looks like a considerable step back even from XP on this front, much less from Windows 7.

That wouldn't be keyboard-accessible, would it? At least not in a "reliable, access it the same way no matter where you start out from" sense. (Plus, what I wanted to know about is what works on any Win8 system, without requiring advance preparation.)

From the look of that Q&A thread, the winner is probably going to be Win+I, a letter or a few keystrokes, and Enter ; the fallback would be Win+C, something to select Settings, and then the same as before. Question is exactly what that "letter or a few keystrokes" would need to be.